Modify /etc/lilo.conf to include append="Append Line" in your current kernel boot section. Again see Section 7.2 for details.

Type /sbin/lilo and reboot

Now you should see your hard disks seperately and you can use them. If you previously had partitions on the RAID mirror, you will see partitions accordingly on each of the two member disks. You will also see the data that you previously stored on the RAID mirror.